Diffusion time dependence of the diffusion weighted
signal for high b-values in ischemic stroke lesions was recently reported,
allowing for the extraction of more information on the tissue microstructure.
Here, we express the diffusion time dependence as a change kurtosis, where
kurtosis reflects the degree of deviation from free diffusion. The changes in
kurtosis for different diffusion times were calculated for nine ischemic stroke
patients, examined at a 3T clinical scanner. The change in kurtosis
successfully visualized the lesions. Changes in kurtosis are suggested to
reflect changes in cell sizes as well as in cell physiology (cellular membrane
functionality).